Disclosed herein are a medical image generation apparatus and medical image generation method that realistically display an object or inner tissues of the object. The medical image generation apparatus includes a sample image extractor configured to extract a sample image from an original image containing color information of an object, a color gamut modeler configured to model a color gamut of the sample image to have a predetermined shape, a 2D color map generator configured to generate a 2D color map based on the modeled color gamut, a volume data generator configured to generate 3D volume data based on a sectional image of inner tissues of the object, and a control unit configured to generate a 3D color medical image by applying values of the 2D color map to a 3D grayscale medical image acquired by volume rendering of the 3D volume data.